diff --git a/homeassistant/components/syncthru/diagnostics.py b/homeassistant/components/syncthru/diagnostics.py
new file mode 100644
index 00000000000..5ff860ed41e
--- /dev/null
+++ b/homeassistant/components/syncthru/diagnostics.py
@@ -0,0 +1,18 @@
+"""Diagnostics support for Syncthru."""
+
+from __future__ import annotations
+
+from typing import Any
+
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant
+
+from .const import DOMAIN
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: ConfigEntry
+) -> dict[str, Any]:
+    """Return diagnostics for a config entry."""
+
+    return hass.data[DOMAIN][entry.entry_id].data.raw()
diff --git a/tests/components/syncthru/snapshots/test_diagnostics.ambr b/tests/components/syncthru/snapshots/test_diagnostics.ambr
new file mode 100644
index 00000000000..9b22561a2d6
--- /dev/null
+++ b/tests/components/syncthru/snapshots/test_diagnostics.ambr
@@ -0,0 +1,193 @@
+# serializer version: 1
+# name: test_diagnostics
+  dict({
+    'GXI_A3_SUPPORT': 0,
+    'GXI_ACTIVE_ALERT_TOTAL': 2,
+    'GXI_ADMIN_WUI_HAS_DEFAULT_PASS': 0,
+    'GXI_IMAGING_BLACK_VALID': 1,
+    'GXI_IMAGING_COLOR_VALID': 1,
+    'GXI_IMAGING_CYAN_VALID': 1,
+    'GXI_IMAGING_MAGENTA_VALID': 1,
+    'GXI_IMAGING_YELLOW_VALID': 1,
+    'GXI_INSTALL_OPTION_MULTIBIN': 0,
+    'GXI_INTRAY_MANUALFEEDING_TRAY_SUPPORT': 0,
+    'GXI_SUPPORT_COLOR': 1,
+    'GXI_SUPPORT_MULTI_PASS': 1,
+    'GXI_SUPPORT_PAPER_LEVEL': 0,
+    'GXI_SUPPORT_PAPER_SETTING': 1,
+    'GXI_SWS_ADMIN_USE_AAA': 0,
+    'GXI_SYS_LUI_SUPPORT': 0,
+    'GXI_TONER_BLACK_VALID': 1,
+    'GXI_TONER_CYAN_VALID': 1,
+    'GXI_TONER_MAGENTA_VALID': 1,
+    'GXI_TONER_YELLOW_VALID': 1,
+    'GXI_TRAY2_MANDATORY_SUPPORT': 0,
+    'capability': dict({
+      'hdd': dict({
+        'capa': 40,
+        'opt': 2,
+      }),
+      'ram': dict({
+        'capa': 65536,
+        'opt': 65536,
+      }),
+      'scanner': dict({
+        'capa': 0,
+        'opt': 0,
+      }),
+    }),
+    'drum_black': dict({
+      'newError': '',
+      'opt': 0,
+      'remaining': 44,
+    }),
+    'drum_color': dict({
+      'newError': '',
+      'opt': 1,
+      'remaining': 44,
+    }),
+    'drum_cyan': dict({
+      'newError': '',
+      'opt': 0,
+      'remaining': 100,
+    }),
+    'drum_magenta': dict({
+      'newError': '',
+      'opt': 0,
+      'remaining': 100,
+    }),
+    'drum_yellow': dict({
+      'newError': '',
+      'opt': 0,
+      'remaining': 100,
+    }),
+    'identity': dict({
+      'admin_email': '',
+      'admin_name': '',
+      'admin_phone': '',
+      'customer_support': '',
+      'device_name': 'Samsung C430W',
+      'host_name': 'SEC84251907C415',
+      'ip_addr': '192.168.0.251',
+      'ipv6_link_addr': '',
+      'location': 'Living room',
+      'mac_addr': '84:25:19:07:C4:15',
+      'model_name': 'C430W',
+      'serial_num': '08HRB8GJ3F019DD',
+    }),
+    'manual': dict({
+      'capa': 0,
+      'newError': '',
+      'opt': 0,
+      'paper_size1': 0,
+      'paper_size2': 0,
+      'paper_type1': 2,
+      'paper_type2': 0,
+    }),
+    'mp': dict({
+      'capa': 0,
+      'newError': '',
+      'opt': 0,
+      'paper_level': 0,
+      'paper_size1': 0,
+      'paper_size2': 0,
+      'paper_type1': 2,
+      'paper_type2': 0,
+    }),
+    'multibin': list([
+      0,
+    ]),
+    'options': dict({
+      'hdd': 0,
+      'wlan': 1,
+    }),
+    'outputTray': list([
+      list([
+        1,
+        50,
+        '',
+      ]),
+    ]),
+    'status': dict({
+      'hrDeviceStatus': 3,
+      'status1': '',
+      'status2': '',
+      'status3': '',
+      'status4': '',
+    }),
+    'toner_black': dict({
+      'cnt': 1176,
+      'newError': 'C1-5110',
+      'opt': 1,
+      'remaining': 8,
+    }),
+    'toner_cyan': dict({
+      'cnt': 25,
+      'newError': '',
+      'opt': 1,
+      'remaining': 98,
+    }),
+    'toner_magenta': dict({
+      'cnt': 25,
+      'newError': '',
+      'opt': 1,
+      'remaining': 98,
+    }),
+    'toner_yellow': dict({
+      'cnt': 27,
+      'newError': '',
+      'opt': 1,
+      'remaining': 97,
+    }),
+    'tray1': dict({
+      'capa': 150,
+      'newError': '',
+      'opt': 1,
+      'paper_level': 0,
+      'paper_size1': 4,
+      'paper_size2': 0,
+      'paper_type1': 2,
+      'paper_type2': 0,
+    }),
+    'tray2': dict({
+      'capa': 0,
+      'newError': '',
+      'opt': 0,
+      'paper_level': 0,
+      'paper_size1': 0,
+      'paper_size2': 0,
+      'paper_type1': 2,
+      'paper_type2': 0,
+    }),
+    'tray3': dict({
+      'capa': 0,
+      'newError': '',
+      'opt': 0,
+      'paper_level': 0,
+      'paper_size1': 0,
+      'paper_size2': 0,
+      'paper_type1': 2,
+      'paper_type2': 0,
+    }),
+    'tray4': dict({
+      'capa': 0,
+      'newError': '',
+      'opt': 0,
+      'paper_level': 0,
+      'paper_size1': 0,
+      'paper_size2': 0,
+      'paper_type1': 2,
+      'paper_type2': 0,
+    }),
+    'tray5': dict({
+      'capa': 0,
+      'newError': '0',
+      'opt': 0,
+      'paper_level': 0,
+      'paper_size1': 0,
+      'paper_size2': 0,
+      'paper_type1': 2,
+      'paper_type2': 0,
+    }),
+  })
+# ---
diff --git a/tests/components/syncthru/test_diagnostics.py b/tests/components/syncthru/test_diagnostics.py
new file mode 100644
index 00000000000..f5988936328
--- /dev/null
+++ b/tests/components/syncthru/test_diagnostics.py
@@ -0,0 +1,29 @@
+"""Tests for the diagnostics data provided by the Syncthru integration."""
+
+from unittest.mock import AsyncMock
+
+from syrupy import SnapshotAssertion
+
+from homeassistant.core import HomeAssistant
+
+from . import setup_integration
+
+from tests.common import MockConfigEntry
+from tests.components.diagnostics import get_diagnostics_for_config_entry
+from tests.typing import ClientSessionGenerator
+
+
+async def test_diagnostics(
+    hass: HomeAssistant,
+    hass_client: ClientSessionGenerator,
+    mock_syncthru: AsyncMock,
+    mock_config_entry: MockConfigEntry,
+    snapshot: SnapshotAssertion,
+) -> None:
+    """Test diagnostics."""
+    await setup_integration(hass, mock_config_entry)
+
+    assert (
+        await get_diagnostics_for_config_entry(hass, hass_client, mock_config_entry)
+        == snapshot
+    )